Meiotic cells tightly regulate the number and distribution of crossovers to promote accurate chromosome segregation. Yokoo and colleagues uncover a metazoan-specific, cyclin-like protein that is crucial for crossover formation. They utilize this protein's unique properties to explore a remarkable example of biological numerology, whereby nearly every meiotic cell in C. elegans makes precisely s...

Clarke, Roy S., Jr., and Joseph I. Goldstein. Schreibersite Growth and Its Influence on the Metallography of Coarse-Structured Iron Meteorites. Smithsonian Contributions to the Earth Sciences, number 21, 80 pages, 28 figures, 20 tables, 1978. —The role that schreibersite growth played in the structural development process in coarse-structured iron meteorites has been examined. The availability ...

Abstract Excavations at the Chalcolithic site Fazael in central Jordan Valley uncovered a large number of metal items, many them polymetallic copper alloys cast lost wax technique. Metallography and SEM–EDS analysis on subset assemblage confirm previous notions metallurgy Southern Levant but extend significantly three aspects: The is slightly depleted its arsenic content compared to assemblages...

Sexual segregation, or the differential use of space by males and females, is hypothesized to be a function of body size dimorphism. Sexual segregation can also manifest at small (social segregation) and large (habitat segregation) spatial scales for a variety of reasons. Furthermore, the connection between small- and large-scale sexual segregation has rarely been addressed. We studied a popula...